https://www.amazon.com/Swanson-Niacinamide-250-Milligrams-Capsules/dp/B00068SIY6/ref=mp_s_a_1_3?keywords=niacinamide+swanson&qid=1563244301&s=gateway&sprefix=niacinamide+swan&sr=8-3
i buy my beta carotene from whole foods which is: https://www.amazon.com/365-Everyday-Value-Carotene-25000/dp/B074H7K39P/ref=mp_s_a_1_1?fpw=fresh&keywords=365+beta+carotene&qid=1563244623&s=amazonfresh&sr=1-1